1. Field of Invention
Embodiments disclosed herein generally relate to methods of designing antennas and antennas designed by those methods. In particular, embodiments relate to antennas with inductively coupled feed.
2. Description of Related Art
Electrically small antennas may include antennas with a size about 10% of the operating wavelength of the antenna or less (e.g., 5% of the operating wavelength). Existing designs for electrically small antennas typically have complicated structures. For example, Goubau (reference 6), Dobbins et al. (reference 7) and Foltz et al. (reference 8) each disclose relatively complex antenna designs. Complicated structures may make antenna fabrication difficult. Complicated structures may also be difficult to redesign to meet different operating frequencies. A concern with many electrically small antennas is that the input resistance of such antennas may be relatively small. The small input resistance may cause difficulty in matching the antenna to the associated radio frequency (RF) system. Certain known designs (e.g., see Altshuler (reference 1), Hansen et al. (reference 9) and Corum (reference 10)) utilize matching circuits to connect the antenna to the rest of the RF system. However, matching circuits may add to the size, loss, complexity and/or cost of the system.